Spring temperature variability over Turkey since 1800 CE reconstructed from a broad network of tree-ring data

Abstract

Abstract. The 20th century was marked by significant decreases in spring temperature ranges and increased nighttime temperatures throughout Turkey. The meteorological observational period in Turkey, which starts ca. 1929 CE, is too short for understanding long-term climatic variability. Hence, the historical context of this gradual warming trend in spring temperatures is unclear. Here we use a network of 23 tree-ring chronologies to provide a high-resolution spring (March–April) temperature reconstruction over Turkey during the period 1800–2002. The reconstruction model accounted for 67 % (Adj. R2 = 0.64, p ≤ 0.0001) of the instrumental temperature variance over the full calibration period (1930–2002). During the pre-instrumental period (1800–1929) we captured more cold events (n = 23) than warm (n = 13), and extreme cold and warm events were typically of short duration (1–2 years). Compared to coeval reconstructions of precipitation in the region, our results are similar with durations of extreme wet and dry events. The reconstruction is punctuated by a temperature increase during the 20th century; yet extreme cold and warm events during the 19th century seem to eclipse conditions during the 20th century. During the 19th century, annual temperature ranges are more volatile and characterized by more short-term fluctuations compared to the 20th century. During the period 1900–2002, our reconstruction shows a gradual warming trend, which includes the period during which diurnal temperature ranges decreased as a result of increased urbanization in Turkey.